Custom Elite Spa Cover / Hot Tub Cover 6" to 4" taper Tapered 6" - 4" inserts forMAXIMUM ENERGY EFFICIENCY & STRENGTH!! 4 tie-down with keyed locks, 2 handles , 2 heat seals Thickness of vapor wrap - 4ml, Foam is vacuum sealed - yes Density of foam  1 lb, Virgin foam - yes Type and ga of metal reinforcement used  galvanized steel 20ga